The reliability of aircraft engines is of critical importance and one technique for improving the reliability of such engines is to estimate the operational lifetime of critical components in the engine and repair or replace those components before they have an unacceptable probability of failure. The ignition system is a critical part of a gas turbine engine and usually comprises an igniter that is used to provide spark to the combustion chamber to initiate or maintain combustion. The ignition system is typically used during engine startup, but can also be used in other situations.
Igniters are subject to wear during use and must be periodically replaced. This wear typically takes the form of erosion of the electrodes on an igniter. Eventually, the erosion can cause the gap between electrodes to become larger, which can negatively impact the reliability of the igniter and may eventually make the igniter inoperable.
Existing methods for estimating the life of igniters have had limited accuracy. Such inaccuracy in life estimation can result in an igniter being repaired or replaced prematurely or, alternatively, result in a failure or degradation of performance before it is replaced.
Improvement is therefore desirable.